1. Field of the Invention
The present invention relates to a traffic distribution device, a traffic distribution method and a packet relay method.
2. Related Background Art
As known well, over the recent years, as schematically shown in FIG. 9, networks (LAN 1 and LAN 2) including a plurality of servers (SV #1-SV #3 in FIG. 9) each having the same function and the same configuration and a server load balancer (SLB #1: refer to, e.g., Patent document 1), have come to link to WAN and the Internet via a router 50.
A throughput of the network having the architecture given above is determined by a high-order layer processing device such as the server load balancer requiring softwarewise processing. Therefore, a scheme performed for improving the throughput of the network using the existing high-order layer processing device (the server load balancer, a firewall, etc.) is that the high-order layer processing device is replaced by a device having a higher function.
Moreover, there is a limit to the throughput attainable by the single high-order layer processing device. Hence, definitions pertaining to the network architecture are changed for desiring to gain a throughput equal to or higher than the throughput attainable by the single high-order layer processing device.
Namely, in the case of simply adding SLB #2 to this network (FIG. 9), a server sided default gateway address of the SLB #1 is IP 11, and consequently there is acquired the network, wherein the servers SV #1-SV #3 send responses to requests given from any SLBs to the SLB #1. Therefore, in the case of desiring to gain the throughput equal to or higher than the throughput attainable by the single high-order layer processing device, the definitions about the network architecture are changed.
[Patent document 1] Japanese Patent Application Laid-Open Publication No. 11-27320